Agricultural Water Tower Domes

In July, 2000, my girlfriend Stacie and I went to Houston, Texas for
the annual conference of the World Future
Society. While there, we drove across part of Texas to visit the
city of Austin, and noticed a huge preponderance of water towers all
across the state...hundreds of them, just in the small area we passed
through. The area of Texas that we were in was also extremely flat. We
drove hundreds of miles and it pretty much remained flat the entire
time. The water towers there are used for storage, irrigation, and to
generate water pressure for the plumbing systems of the surrounding
communities.

The other thing we noticed was that, like in California, and most
other places, the irrigation water was being sprayed onto open
cropland, where it could promptly evaoporate and blow away. In very
real terms, this is roughly equivalent to spraying a garden hose onto a
hot rock or sidewalk. Try it sometime and watch what happens to the
water.

This is something that has bothered/annoyed me for a number of
years. We keep hearing about the need to conserve water, and the
droughts that California and other western states constantly go
through, yet if you go for a drive into the agricultural regions,
you'll find farmers spraying millions of gallons of water onto hot rock
every day, letting it evaoprate and blow away, then complaining that
there's not enough water. This is daft, to put it politely.

I've studied fabric-structure architecture, such as you see in park
pavilions, sports arenas, and the like, and for years I'd been trying
to think of ways to enclose the agricultural fields in some sort of
lightweight, transparent vapor-barrier structure, so as to retain that
precious water. It seems to me that one could reduce water consumption
by a large amount, perhaps as much as 80-90% by employing such a
method.

Seeing the water towers in Texas really made it click. I suddenly
envisioned a complete system that could be manufactured offsite,
delivered by airship, and erected in an area in about a day. This
system would have an inflated dome made of a tough, clear material,
such as Tefzel, which could act as a vapor barrier, protection against
the elements and pests, and also function as a gigantic greenhouse. It
would have an atmospheric condenser at the top of the tower, to draw water vapor
out of the air and keep the tower filled without needing to drill wells
or pump water out of the local water table. The runoff from any rain
that hit the dome could also be collected at the perimeter, and drawn
up into the tower for storage.

The top of the tower would also house solar power panels and windmills
to generate all local power needs, as well as perhaps selling excess
power back into the electrical grid, and could even have an observation
deck for local sightseeing, weather observation, housing, etc.

I've also noticed in driving and flying around the country that some
farms use irrigation equipment that goes around in a giant circle. So
they are already using the circular field design depicted here, but
they aren't retaining any moisture from their waterings, so they have
to keep pumping it from somewhere. They also arrange these circular
fields in a square-based grid pattern, like a tic-tac-toe game, rather
than in a closest-packing arrangement, which utilizes the space more
efficiently, and leaves less land wasted. You can see some other
closest-packing arrangements here. In the two top-level views shown here, note the difference
in wasted space. Even if you were to push the domes right up to the
edges of each other (which you might not want to do if you want to have
access roads between them), the non-closest-packing arrangement has
obvious waste areas, which to a farmer equals lost cropland, and lost
profits.

And here's a view of how I envision a cluster of these agri-domes
appearing from the air:

The renderings on this page were made with Bryce
3D.

Fellow Domesteading list member,
Chuck Knight provided me with some scans of the work of Frei Otto, who was
a German architect specializing in fabric structures. In fact, I used to
study his work specifically in my architecture and fabric structures
classes and it inspired some of my own design work.

It appears Frei Otto had the same idea, and even came up with a great
solution for large span coverings. The use of anticlastic (saddle-shaped)
curves allows the membrane to undulate across a large area, and also
provides for rainwater collection points in all of the depressions in the
membrane.